Ground Water

Case Study: San Antonio

OVERVIEW

A client of G3SoilWorks was considering purchasing a multi-million dollar piece of property in San
Antonio, Texas that allegedly contained two large springs with massive amounts of fresh water. The
current landowner and drilling company claimed that the two groundwater springs they found were
interconnected to the Trinity and Edwards aquifers. The client planned on purchasing the water
resource and selling the product to the water district. Multiple local firms and individual
hydrogeologists in Texas confirmed to the client that the land was good and should be purchased. The
client called G3SoilWorks to confirm whether the property was connected to the aquifers and whether
it would successfully provide water over an extended period of time without impacting other
aquifers.

Previous to the arrival of G3SoilWorks, the drilling company unloaded 10,000 gallons of hydrochloric
acid down the well to dissolve the calcium carbonate in the limestone in an attempt to increase the
size of the well opening and improve water yield. While that increased the speed at which the water
could be pumped, it did not improve the amount of water available from the well. In order to confirm
whether water was coming from sustainable ground water, G3SoilWorks applied monitoring devices on
the two different wells. The first well quickly dewatered and the ground water never returned. The
pump test for the second well showed that the water curve dropped and then rose instead of leveling
out.

PROBLEM

Water curve shows a decline and then increase in groundwater pump test.

Standard water pump tests show the curve stabilizing or decreasing based on supply and
sustainability.

G3SoilWorks needed to confirm why the curve increased instead of stabilizing from available
water.

SOLUTION

After confirming with the landowner and drilling company’s hydrogeologist that the ground and surface
water did not communicate, Larry Fanning investigated the land surrounding the springs. Within an
hour he found a stream that dried out near a sinkhole. They found that groundwater was funneling
into a sinkhole, which supplied the spring with water. G3SoilWorks was able to trace the ground
water near the sinkhole back to the spring, and further discovered that the water pumped from the
spring was supplying this stream, essentially creating a chain.

CONCLUSION

G3SoilWorks was able to provide evidence to the client against purchasing this land, for a reasonable
amount. The client was spared from spending multi-millions on purchasing land that did not provide
promised quantities of fresh ground water.